Pour boiling water over the mushrooms and soak for 10 minutes. Cook the rice, following pack instructions.
Meanwhile, heat the oil in a large frying pan and add the onion and leeks. Cook for 10 minutes, until soft, then increase the heat. Add the chicken and cook for a further 5 minutes until beginning to brown.
Add the wine, bring to the boil then simmer for 5 minutes, until reduced by half. Then pour in the stock and cook for a further 5 minutes.
Drain the mushrooms and add to the pan with the crème fraîche and half the parsley. Stir well, then serve with the rice and garnish with the remaining parsley.